Biomedical subjects

M T Schultheis

Publications and source records attributed to M T Schultheis.

6 recordsLinked to original sources

PubMed2003

Spacing of repetitions improves learning and memory after moderate and severe TBI.

Extensive research has determined that new learning in healthy individuals is significantly improved when trials are distributed over time (spaced presentation) compared to consecutive learning trials (massed presentation). This phenomenon known as the "spacing effect" (SE) has been shown to enhance verbal and nonverbal learning in healthy adults of different ages and in different memory paradigms (e.g., recognition, recall, etc.). The purpose of this study was to examine whether learning in adults with moderate and severe traumatic brain injury (TBI) is improved using a spacing-of-repetitions procedure. Using a within-groups design, participants with TBI (n = 20) were presented a list of 115 words that were presented either once (single condition), twice consecutively (massed condition), or twice with 11 words between presentations (spaced condition). Participants were required to rank each word from 1 to 10 according to their familiarity with the word; they were not asked to "memorize" words for a later test. Word list learning was measured with a free recall test immediately following list presentation and with free recall and recognition tests after a 30-min delay. Participants recalled and recognized significantly more spaced words than massed words during this word list learning task. These results strongly indicate that the spacing of repetitions improves learning and memory in individuals who have sustained moderate to severe TBI. Implications for rehabilitation are discussed.

Adolescent↗

PubMed2001

The influence of cognitive impairment on driving performance in multiple sclerosis.

OBJECTIVE: To examine the influence of impaired cognitive processing on measures of driving skills in persons with MS. METHODS: Twenty-eight subjects with documented MS were divided into two groups-with [MS(+), n = 13] and without [MS(-), n = 15] cognitive impairment-based on neuropsychological performance. Healthy control (HC) subjects (n = 17) matched on age and driving experience were also studied. Driving-related skills were compared between the groups based on performance on two computerized driving tests: the Useful Field of Vision (UFOV) and the Neurocognitive Driving Test (NDT). RESULTS: The MS(+) group performed significantly worse than both the MS(-) and HC groups in the latency to perform several driving-specific functions on the NDT, but no overall group differences were observed in actual errors on the NDT. On the UFOV, when compared to MS(-) and HC subjects, the MS(+) group demonstrated poorer performance on two of the three subtests. Additionally, a significantly higher percentage of MS(+) individuals were rated within the high risk (probability of crash involvement) category, relative to the MS(-) and HC groups. CONCLUSIONS: Cognitive impairment can negatively affect driving-related skills in persons with MS and should be considered in the determination of driving ability.

Adult↗

PubMed2001

Impaired delay eyeblink classical conditioning in individuals with anterograde amnesia resulting from anterior communicating artery aneurysm rupture.

Anterior communicating artery (ACoA) aneurysm rupture can lead to an anterograde amnesia syndrome similar to that observed after damage to the hippocampus and medial temporal lobes (MT). It is currently believed that ACoA amnesia results from basal forebrain damage that disrupts hippocampal processing without direct hippocampal damage. Converging evidence from animal studies and computational modeling suggests that qualitative differences may exist in the pattern of memory impairment after basal forebrain or MT damage. For example, animals with basal forebrain but not hippocampal damage are impaired at delay eyeblink classical conditioning (EBCC). In this study, individuals with ACoA amnesia were shown to be impaired at delay EBCC compared with matched controls; this contrasts with the spared delay EBCC previously observed in MT amnesia. This finding suggests the beginning of a possible dissociation between the memory impairments in MT versus ACoA amnesia.

Adult↗

PubMed2000

Acquisition versus retrieval deficits in traumatic brain injury: implications for memory rehabilitation.

OBJECTIVE: To examine whether impaired memory in persons with traumatic brain injury (TBI) is caused by impaired initial acquisition or compromised retrieval from long-term storage. DESIGN: Prospective matched controlled trial. SETTING: Postacute rehabilitation institute. PARTICIPANTS: Patients with moderate to severe TBI (n = 28) and 21 matched, healthy controls (HCs). MAIN OUTCOME MEASURES: Patients with TBI and HC subjects were equated on initial acquisition on a verbal list-learning task. Recall and recognition performance was then evaluated at 30- and 90-minutes after learning. RESULTS: All HC subjects and 20 subjects with TBI (TBI-MET) were able to meet the learning criterion, but the TBI-MET group took significantly more trials than HC subjects to do so. However, after equating groups on acquisition, the TBI-MET group did not differ from controls on recall and recognition at both the 30- and 90-minute delays. Eight TBI subjects showed severe learning deficits (TBI-NOT MET) because they never learned the task, and showed significantly impaired recall and recognition performance. The 2 TBI groups did not differ on measures of severity of injury, but the TBI-NOT MET group performed significantly below the TBI-MET group on executive functioning. Rate of forgetting did not differ across the 3 groups. CONCLUSIONS: Results suggest that memory impairment after TBI is caused primarily by deficiencies in initial acquisition of verbal information rather than in compromised retrieval. The findings have significant implications for the rehabilitation and treatment of individuals with TBI.

Adolescent↗

PubMed2000

Fractioning the Hooper: a multiple-choice response format.

The Hooper Visual Organization Test (HVOT) provides an excellent illustration of the multifactorial nature of most neuropsychological tests. Although the HVOT clearly requires certain visual perceptual skills, the test also demands that the subject produce an overt verbal response - i.e., the name of the object that has been cut up and rearranged. Thus, individuals with disorders of confrontation naming may obtain low scores on the HVOT by virtue of their anomia, even if the primary perceptual skills that the HVOT purports to assess are intact. The present study was designed to minimize the demands of object naming on HVOT performance, by using a multiple choice format of the HVOT. Fourteen individuals with lateralized injury resulting from either cerebral vascular accident or cerebral contusion were administered the Boston Naming Test (BNT) and the standard version of the HVOT. Approximately 24 hours later, subjects were administered the Multiple-Choice Hooper Visual Organization Test (MC-HVOT). The MC-HVOT consisted of the 30 original HVOT stimuli presented with four response choices, including the correct response and three foils. A paired sample t test revealed that anomic subjects achieved a significantly greater number of correct responses on the MC-HVOT then under the standard HVOT administration. Subjects with both right and left hemisphere involvement benefited from diminished naming demands. Overall HVOT performance significantly improved when the object naming demand was reduced, resulting in a clearer assessment of visual integration skills. These findings may have significant implications for both interpretation of impairment and formulation of treatment recommendations.

Adult↗

PubMed1998

An interpretive table for the Visual Form Discrimination Test.

The capacity to analyze complex visual stimuli is susceptible to several forms of brain dysfunction. The Visual Form Discrimination test is a 16-item multiple-choice measure requiring visual discrimination and matching. Published normative observations provide frequency counts of various raw scores but lack certain critical information, e.g., standard deviations, needed for clinical interpretation of performance in individual cases. The purpose of this study was to improve the clinical utility of the test by (1) reporting the standard deviation of the normative sample and (2) using this index to create a table to foster interpretation in single cases. We provide T scores, percentile equivalents, and clinical descriptors for various raw scores, permitting clinicians to make more precise use of the Visual Form Discrimination.

Adult↗